Alkyl Bridge Length to Bias the Kinetics and Stability of Consecutive Supramolecular Polymerizations,Small Methods

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Alkyl Bridge Length to Bias the Kinetics and Stability of Consecutive Supramolecular Polymerizations
Small Methods ( IF 10.7 ) Pub Date : 2019-11-26 , DOI: 10.1002/smtd.201900715
Elisa E. Greciano ₁ , Silvia Alsina ₁ , Goutam Ghosh ₂ , Gustavo Fernández ₂ , Luis Sánchez ₁

Affiliation

Herein, the impact of alkyl bridge length is unraveled on the self‐assembly of N‐annulated perylenetetracarboxamides 1–4 that cooperatively form supramolecular polymers. Spectroscopic studies in different solvents as media for the self‐assembly demonstrate the impact that the length of the bridge separating the two amide groups of compounds 1–4 exerts on the supramolecular polymerization process: i) in MCH/Tol (8/2), compounds 1–3 exhibit a consecutive process that, however, it is not operative for 4; ii) the presence of three methylene units in 2, which can induce a parallel distribution of the amide groups, notably decreases the stability of the corresponding aggregates in Tol; iii) increasing the spacer length accelerates the conversion of the metastable, intramolecularly H‐bonded monomeric species, which prevents to develop seeded supramolecular polymerizations; iv) the presence of a spacer with five methylene units in 4 hinders the formation of the corresponding 10‐membered pseudo‐cycle; and v) only the higher relative stability of the inactivated monomeric species of 1 enables pathway complexity, with a kinetically controlled self‐assembly to yield nanoparticles and a thermodynamically controlled supramolecular polymerization to achieve fibrillar structures. The results presented herein expand the knowledge on the structure/property relationship for self‐assembling units to provide pathway complexity and to bias the kinetics and stability of the supramolecular aggregates.

中文翻译：

烷基桥的长度偏向于连续超分子聚合的动力学和稳定性

在本文中，烷基桥长的影响对N环化per四甲酰胺1-4的自组装产生了影响，后者共同形成了超分子聚合物。在不同溶剂中作为自组装介质的光谱研究表明，分隔化合物1-4的两个酰胺基的桥的长度对超分子聚合过程有影响：i）在MCH / Tol（8/2）中，化合物1-3表现出一个连续的过程，但是对于4而言则无效。ii）在2中存在三个亚甲基单元，其可以诱导酰胺基团的平行分布，显着降低Tol中相应聚集体的稳定性；iii）增加间隔基长度可加速亚稳分子内H键键单体物种的转化，从而阻止发展种子化的超分子聚合反应；iv）4个带有5个亚甲基单元的间隔基的存在阻碍了相应的10元假环的形成; v）只有1个灭活的单体物种具有较高的相对稳定性通过动力学控制的自组装产生纳米颗粒，并通过热力学控制的超分子聚合来获得原纤维结构，从而实现途径的复杂性。本文介绍的结果扩展了自组装单元的结构/性质关系的知识，以提供途径复杂性并偏向超分子聚集体的动力学和稳定性。

更新日期：2019-11-27

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